startTime = DateTime.Now;
DispatcherTimer dt = new DispatcherTimer();
dt.Interval = new TimeSpan(0, 0, 1);
dt.Tick += new EventHandler(dt_Tick);//調(diào)用函數(shù)
dt.Start();
void dt_Tick(object sender, EventArgs e)
{
   timeSpan = DateTime.Now.Subtract(startTime);
   //用TimeSpan來(lái)格式化時(shí)間
   timer1.Content = string.Format("{0:00}:{1:00}:{2:00}", (int)timeSpan.TotalHours,timeSpan.Minutes, timeSpan.Seconds);
   //用DateTime來(lái)格式化時(shí)間
   timer2.Content = String.Format("{0:HH:mm:ss}", new DateTime(timeSpan.Ticks));
}